Dedicated Bifurcation Stents Strategy

Coronary bifurcation lesions represent an area of ongoing challenges in interventional cardiology, mainly due to the higher rate of residual stenosis and restenosis at the side branch ostium. Multiple two-stent bifurcation strategies, including T-stenting, V-stenting, simultaneuos kissing stenting, culotte stenting and classic crush techniques, have no advantages over one-stent techniques. This led to provisional stenting being considered as a mainstream approach, based on the results of numerous randomised trials. Dedicated bifurcation stents have been designed specifically to treat coronary bifurcations with the aim of addressing some of the shortcomings of the conventional percutaneous approach and facilitating the provisional approach. The development of more drug-eluting platforms and larger studies with control groups demonstrating their clinical applicability, efficacy and safety are required before these stents are widely incorporated into daily practice.

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Bifurcation lesions account for approximately 20–30% of all percutaneous coronary interventions (PCIs). Coronary bifurcation sites are prone to developing obstructive atherosclerotic disease due to turbulent blood flow and change of shear stress. With the complexity of bifurcation lesions, several classification systems have been advocated in order to extablish percutaneous strategies.1–3 In fact, dedicated quantitative coronary angiography (QCA) software is still needed to overcome the shortcomings of conventional QCA.4 Most importantly, a suboptimal result in the side branch (SB) due to residual stenosis at the SB may not be physiologically significant, even in the modern era of drug-eluting stents (DES).5–7 As a result, optimised provisional stenting is the treatment of choice.8–10 However, in some situations where bifurcation lesions have certain anatomical configurations or bifurcation angles, two-stent techniques are critically needed. This article will summarise the recent development of dedicated bifurcation stents.11–29

Abbott Frontier™

The Abbott Frontier™ (Abbott Vascular Devices, Redwood City, CA, US/Guidant Corporation, Santa Clara, CA, US) coronary stent (see Figure 1B) system is a balloon-expandable stainless-steel stent pre-mounted on a dedicated delivery system with two balloons (monorail for the main branch [MB] vessel and an over-the-wire inner lumen for the SB vessel) and two guidewire lumens. To assist tracking and avoid guidewire crossing, the Abbott Frontier has an integrated tip design that allows single tip delivery; the MB balloon tip includes a pocket on the distal sleeve for joining the MB and SB balloon tips with a mandrel. The Abbott Frontier is advanced into the MB over a conventional wire. The joining mandrel is then retracted, releasing the over-the-wire SB tip, and a 300cm wire is inserted into the SB balloon lumen and into the SB. The system is advanced to the carina and simultaneous kissing inflation of the two balloons is performed, using a single indeflator, to expand the stent on the MB and SB. The next generation of the Abbott Frontier will be a chromium–cobalt stent using the Xience DES platform.